JP2723801B2 - Gas shielded arc welding wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved wire for gas shielded arc welding.

[0002]

2. Description of the Related Art The performance of gas shielded arc welding used in the manufacturing processes of industrial machines, automobiles, steel frames, etc., is becoming increasingly demanding year by year, and improvements have been made to achieve high speed, high quality and high efficiency. It has been done. As one means of improving such a gas shielded arc welding method, examination of a shield gas component, inverter control of a welding power source, and the like are performed.

However, in order to efficiently obtain a high quality weld at low cost, it is most important to prevent defects caused by instability of the welding arc and maintain a stable welding arc for a long time. The instability of the welding arc referred to here means, for example, a short arc break that cannot be recognized by the naked eye and a short-circuit short-circuit between the wire and the molten pool (hereinafter, short-circuit). Etc.). When the welding wire becomes unstable, the shape of the molten pool fluctuates irregularly, and defects in the bead shape such as undercut and overlap easily occur.
In addition, in multi-layer welding, slag entrainment defects are likely to occur. In addition, the unstable arc promotes the generation of spatter to lower the welding quality, and also causes fatigue of the operator, resulting in lower welding efficiency.

Various efforts have been made to stabilize the arc. For example, Japanese Patent Publication No. 3-77035 discloses that after removing residual lubricant, a potassium carboxylate is fixed on the wire surface, and the amount of the fixation and the amount of free iron powder or free copper powder generated in the fixing process are regulated. By
Techniques for stabilizing the arc discharge phenomenon have been proposed.
In Japanese Patent Application Laid-Open No. 61-3696, the amount of copper powder remaining on the surface of a copper-plated wire is regulated to prevent wear of a current-carrying copper tip and blockage of a flexible conduit tube for feeding the wire. Technology has been proposed.

[0005]

However, in the above-mentioned prior art, the occurrence of short-time arc breaking and short-circuiting, which cannot be recognized by the naked eye, cannot be sufficiently reduced. To prevent fatigue of the elderly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to reduce the occurrence of spatter and to reduce the short-circuit between the wire and the molten pool and the unstable state of the arc such as the breakage of the arc. It is an object of the present invention to provide a gas shielded arc welding wire capable of sufficiently reducing occurrence of welding defects and fatigue of an operator.

[0007]

Gas shielded arc welding wire according to the present invention SUMMARY OF THE INVENTION may, impurities wire surface regulated below 1 cm ² per 5μg wire apparent surface area, the
Among the wire surface impurities, filter paper with a pore size of 10 μm (membrane
The weight of the material that does not pass through the
Restricted to 40% by weight or less of the surface impurity mass,
The amount of copper in the surface impurities (in the case of copper compounds,
) Is 30% by weight or more, and the amount of Ca in all the wires is 10 %.
ppm or less, and the surface Ca content is regulated to 3 ppm or less.

However, in the present invention, the mass of wire surface impurities is measured by the following method. Ultrasonic cleaning of the mass wire of wire surface impurities in an organic solvent such as petroleum ether,
After removing the wire main body from the organic solvent, the organic solvent is filtered using a filter paper (membrane filter) having a pore size of 0.2 μm, and the residue on the filter paper is regarded as a wire surface impurity. The mass of the wire surface impurities was obtained by measuring the weight of the residue on the filter paper. According to this method, except for the feeding lubricant and the rust-preventive oil and fats that are soluble in the organic solvent, other dust, the remaining wire drawing lubricant, and the wire drawing lubricant that has been altered,
Copper powder, iron powder, and alkali or alkaline earth compounds attached as an arc stabilizer can be effectively measured.

The mass of this wire surface impurity is per 1 cm ^{2 of the} apparent surface area of the wire. Therefore, a value obtained by dividing the extracted total impurity amount by the apparent surface area of the wire is the wire surface impurity amount. The apparent surface area of this wire is
It is expressed by the following equation 1.

[0010]

## EQU1 ## (Apparent surface area of wire) = (Average value of wire diameter) × (Pi) × (Length of wire) The amount of surface Ca is measured by the following method. Surface Ca amount The wire is immersed in an appropriate acid such as hydrochloric acid to completely dissolve the plating layer on the surface of the wire and further dissolve a small amount of the wire core thereunder. The total weight of the wire before immersion in the acid is a gram, the weight of the dissolved wire is b gram, and the weight of Ca present in the dissolved wire is determined by analysis of the acid to obtain c _1. and g, when the Ca concentration of the remaining wire core without being dissolved was d ₁ (%), since the amount of Ca was present in the wire core, which is slightly dissolved is calculated by b × d _1/100 And the amount of surface Ca can be obtained from the following equation (2).

[0011]

In Equation 2] surface Ca amount _{(ppm) = {(c 1} -b × d 1/100) / a} × 1000000 present invention, filtration pore size was as described above using a 0.2μm filter paper Of the wire surface impurities extracted by the above process, the mass of the wire surface impurities that do not pass through a filter paper (membrane filter) having a pore diameter of 10 μm is reduced to 40% by weight or less of the total wire surface impurity mass, and the amount of copper component of the total wire surface impurities ( (Copper compound is converted to copper)) at 30% by weight or more.

[0012] In the second aspect, the wire surface impurities,
Na and / or K should be 0.1 to 1 respectively in all wires including wire surface deposits such as feed lubricant and rust preventive oil and fat.
Contains 0 ppm.

Further, in claim 3 , when the wire solid surface portion is formed by combining a plating layer, an interface between the plating layer and the wire core portion, and about several tens μm of the surface of the wire core portion, It is characterized in that the solid surface Na and / or the solid surface K are contained in a total amount of 0.1 ppm or more.

In this case, the solid surface Na is measured by the following method. The solid surface Na wire is degreased with an organic solvent, immersed in an appropriate acid such as hydrochloric acid, to completely dissolve the plating layer on the wire surface, and further dissolve a small amount of the wire core thereunder. The total weight of the wire before immersion in the acid is a gram, the weight of the dissolved wire is b gram, and the weight of Na present in the dissolved wire is determined by analysis of the acid to obtain c _2. G, and the Na concentration of the wire core remaining undissolved is d.
₂ when a (%), the amount of Na was present in the wire core, which is slightly dissolved is calculated by b × d _2/100, solid surface Na is calculated from the following equation 3.

[0015]

Equation 3] the solid surface Na (ppm) = {(c 2 -b × d 2/1
00) / a｝ × 1,000,000 Similarly, the solid surface K is measured by the following method. The solid surface K wire is degreased with an organic solvent, immersed in an appropriate acid such as hydrochloric acid, to completely dissolve the plating layer on the wire surface, and further dissolve a small amount of the wire core thereunder. The total weight of the wire before immersion in the acid is defined as a gram, the weight of the dissolved wire is defined as b gram, and the K weight present in the dissolved wire is further obtained by analyzing the acid to obtain c _3. G, and the K concentration of the wire core remaining without being dissolved is d.
₃ when a (%), the amount of K that existed wire core which is slightly soluble is determined by b × d _3/100, solid surface K is determined from the following equation 3.

[0016]

Equation 3] the solid surface K (ppm) = {(c 3 -b × d 3/10
0) / a｝ × 1,000,000 In the invention according to claim 5, the total oxygen content of the wire is 30 to 200 ppm and the surface oxygen content is 20 to 180 p.
pm.

However, the total oxygen content of the wire is measured by the following method. Total oxygen content of the wire The surface of the wire is degreased with an organic solvent and dried, and the measured oxygen content is defined as the total oxygen content (ppm).

The surface oxygen content is measured by the following method. Surface oxygen content The surface oxygen content (ppm) is obtained by subtracting the oxygen content of the wire core after grinding the thickness of 50 μm or more on the wire surface from the total oxygen content of the wire.

[0019]

According to the results of observation of the welding arc phenomenon using a high-speed video camera and a data recorder, and the analysis results of the wire and the wire surface, the substance adhering to the wire surface is determined by the electric current between the current-carrying tip and the wire. Disruptive contact,
The arc was found to be unstable. The deposits on the surface of the wire include dust, residual wire drawing lubricant, a modified wire drawing lubricant, copper powder, iron powder, and alkali or alkaline earth compounds attached as an arc stabilizer. is there.

In other words, considering the electrical contact between the current-carrying chip and the wire, any substance adhering to the wire surface has a bad effect. However, depending on the substance, the influence is large or small, and a substance having a large dimension has a greater adverse effect than the difference in the components, and a metal-based wire surface impurity tends to have a smaller adverse effect than a non-metal-based wire surface impurity. Admitted.

There are various methods for analyzing the substance adhering to the surface of the wire, but as a result of a number of experimental studies by the present inventors, the method of ultrasonically cleaning the wire in an organic solvent such as petroleum ether is most preferable. Was effective. According to this method, a wire of several kg or more can be easily analyzed, so that a trace amount of wire surface impurities can be accurately captured.

The degree of the ultrasonic cleaning at this time is too strong so that a sound wire surface is damaged to generate copper powder and iron powder, and it is necessary to prevent the wire surface from being damaged. As for the cleaning time, the ultrasonic cleaning time of the wire is gradually increased, and the process is terminated when the amount of impurities on the wire surface is stabilized.

Further, in the present invention, from the viewpoint of electrical contact between the conducting chip and the wire, the amount (μg) of the impurity on the wire surface is defined as the amount per 1 cm ^{2 of the} apparent surface area of the wire.

Furthermore, it has been found that in order to reduce the amount of spatters generated, it is necessary to reduce the Ca content of the wire in addition to stabilizing the arc by reducing the wire surface impurities. In particular, it is effective to reduce not only the amount of Ca in the entire wire but also the plating and the interface between the plating and the wire core and the Ca on the surface of the wire core.

There are various methods for analyzing Ca on the surface of the wire, but as a result of experimental supply by the present inventors, the above-described method for measuring the amount of surface Ca was most effective. According to this method, only the surface portion can be easily analyzed, so that a trace amount of Ca can be captured with high accuracy. Regarding the degree of acid dissolution at this time, the dissolution time is gradually increased from the time when the plating is almost dissolved, and the time when the amount of Ca is stabilized until the surface of the wire core is slightly dissolved is set as the end point.

Further, in order to further stabilize the arc, it is necessary to make the transfer of the droplet at the tip of the wire more stable. For that purpose, it has been found that it is effective to contain one or two kinds of Na and K in addition to reducing the wire surface impurities and reducing the Ca content of the wire. In particular, not only these Na and K are contained in the entire wire, but also a portion considered as a wire solid surface portion, that is, a plating layer, an interface between the plating layer and the wire core portion, and a wire core surface, And / or K was found to be more effective. this is,
Na and K on the surface of the wire are
It is presumed that they are emitted into the arc space at a location that is more effective for arc stability than K and K and Na and K in the wire core. It seems that Na and K in the wire surface deposits are released early from the portion that has exited the current-carrying tip, and that Na and K in the wire core are not effectively released until they become suspended droplets. .

Although various methods for analyzing Na and K on the surface of the wire can be considered, as a result of various tests, the above-described method for measuring solid surface Na and solid surface K, which is the same method as Ca, was effective. . In this method, only the surface portion can be easily analyzed, so that trace amounts of Na and K can be captured with high accuracy. At this time, the degree of acid dissolution is also increased by increasing the dissolution time from the time when the plating layer is almost dissolved, and until the Na amount or the K amount becomes stable within the range until the surface of the wire core is slightly dissolved. And

Further, when the amount of oxygen on the surface of the wire is controlled in an appropriate range, the transfer of the droplet becomes smooth.

Next, the reasons for limiting the numerical values in the present invention will be described. Wire surface impurity amount: 5 μg / cm ^{2 When the} wire surface impurity amount exceeds 5 μg / cm ² , the arc becomes unstable, the arc breakage and short circuit increase remarkably, and welding defects such as undercut and overlap easily occur. Therefore, the worker easily feels fatigue. When the amount of impurities on the wire surface is further reduced to 2 μg or less, more excellent effects can be obtained.

Large-grain impurities: 40% by weight or less, in impurities
Copper content: 30% by weight or more, the mass of large wire surface impurities that do not pass through a filter paper (membrane filter) having a pore size of 10 μm is reduced to 40% by weight or less of the total mass of the extracted surface impurities, and the copper in the total impurities is extracted. The workability is improved by setting the component amount (copper compound is converted to copper) to 30% by weight or more and reducing impurities of large grains to a predetermined amount or less and increasing the copper component amount in the impurities.

Ca content in all wires: 10 ppm or less, surface
Ca amount: 3 ppm or less When the Ca amount in the wire exceeds 10 ppm, the amount of spatter generated increases rapidly. Therefore, the amount of Ca in the wire is reduced to 10 ppm
It is preferable to reduce the amount to less than 3 ppm, but if the amount is further reduced to 3 ppm or less, the amount of spatter generated is sharply reduced, so that better results can be obtained.

When the amount of Ca exceeds 3 ppm, the amount of spatters increases rapidly. Therefore, the surface Ca amount is 3 pp.
m or less, but if the amount of surface Ca is further reduced to 1 ppm or less, the spatter generation amount is sharply reduced, so that better results can be obtained.

Na and / or K in all wires:
Arc is stable when one or two kinds of Na and K are contained in each wire containing 0.1 to 1 ppm or more in all wires including wire surface impurities such as 1 to 10 ppm wire surface impurities, feed lubricant or rust preventive oil and fat. Therefore, the worker's feeling of fatigue is reduced, but less than 0.1 ppm is insufficient. Further, when Na and / or K are contained in the range of 0.2 ppm to 5 ppm, respectively, the stability of the arc is greatly improved, and better results can be obtained. If either Na or K exceeds 10 ppm, the arc concentration is undesirably greatly reduced. At least one of Na and K may be added, but when added, the content needs to be 0.1 to 10 ppm.

Solid surface Na and solid surface K: 0.1 each
When 1 or 2 kinds of Na or K are contained in the surface fixing portion of the wire to 10 ppm ,
Arc stability is significantly improved and workability fatigue is further reduced, but less than 0.1 ppm is insufficient. 0.5ppm
When contained, the stability of the arc is greatly improved,
Better results are obtained. If either Na or K exceeds 10 ppm, the arc concentration is undesirably greatly reduced.

The total oxygen content of the wire: 30 to 200 ppm,
Surface oxygen content: 20 to 180 ppm, and the total oxygen content of the wire is 30 to 200 ppm,
Further, when the surface oxygen amount is 20 to 180 ppm, the transfer of the droplet becomes smooth, and the feeling of fatigue of the operator is reduced.
In this range, fine cracks in the direction inclined about 45 ° from the circumferential direction of the wire having a length of about several tens of μm are often observed on the wire surface, and several μm on the surface of the wire.
In many cases, grain boundary oxidation with a depth of about 10 μm to several tens μm and fine oxides with a submicron size are observed. However, if the total oxygen content of the wire is less than 30 ppm, the effect is insufficient, and if it exceeds 200 ppm, the adhesion of the plating deteriorates. If the surface oxygen content is less than 20 ppm, the effect is insufficient, and if it exceeds 180 ppm, the adhesion of the plating deteriorates. When the surface oxygen content is in the range of 30 ppm to 100 ppm, the stability of the arc is greatly improved and the feeling of fatigue is less, so that better results can be obtained.

The composition of the solid wire for welding may be any composition within the range specified in JIS Z3312, and the effect of the present invention can be sufficiently exhibited. For example, C: 0.001 to 0.15% by weight, Si: 0.30 to 1.10% by weight, Mn: 0.85
-2.60% by weight, P; 0.001-0.030% by weight
Hereinafter, S: 0.001 to 0.030% by weight or less, Cu;
Desirably, the composition contains 0.01 to 0.50% by weight or less, with the balance being iron and unavoidable impurities.

C: 0.001 to 0.15% by weight C is an indispensable component for obtaining deoxidation and strength of the weld metal, but if less than 0.001% by weight, both deoxidation and strength are insufficient. In addition, if the content exceeds 0.15% by weight, hot cracking tends to occur in the weld metal.
0.15% by weight is desirable.

Si: 0.30 to 1.10% by weight Si is an indispensable component for deoxidizing the weld metal.
If it is less than 0.30% by weight, deoxidation is insufficient.
If it exceeds 10% by weight, the toughness of the weld metal tends to decrease, so that 0.30 to 1.10% by weight is desirable.

Mn: 0.85 to 2.60% by weight Mn is an indispensable component for obtaining deoxidation and strength of the weld metal, but if it is less than 0.85% by weight, both deoxidation and strength are insufficient. If the content exceeds 2.60% by weight, low-temperature cracking is likely to occur in the weld metal.
0% by weight is desirable.

P: 0.001 to 0.030% by weight or less P is an indispensable component for obtaining a smooth detachment of the droplet from the tip of the wire. If the content is more than 0.030% by weight, the weld metal is liable to generate hot cracks.
0.001 to 0.030% by weight is desirable.

S: 0.001 to 0.030 wt% or less S is an indispensable component for obtaining a smooth detachment of the droplet from the tip of the wire. If the content is more than 0.030% by weight, the weld metal is liable to generate hot cracks.
0.001 to 0.030% by weight is desirable.

Cu: 0.01 to 0.50 wt% or less Cu is an indispensable component for obtaining the electrical conductivity of the wire and the strength of the weld metal. If it is insufficient, and if it exceeds 0.50% by weight, hot cracking is apt to occur in the weld metal.
It is preferably from 0.01 to 0.50% by weight. Cu may be in the form of plating on the surface of the wire, in the form of a solid solution, or in the form of a wire grain boundary precipitate, but in order to improve the electrical conductivity of the wire, It is desirably 0.10 to 0.40% by weight in the form of plating.

The balance: iron and unavoidable impurities As unavoidable impurities, for example, Be, B, N, Mg,
Ca, V, Co, Zn, As, Se, Sr, Y, Nb,
Cd, In, Sn, Sb, Te, Ba, W, Hg, T
l, Pb, Bi and the like.
It may contain 5% by weight or less, and a total of 0.50% by weight or less. It is desirable that the amount of wire surface impurities be small, but unnecessarily removing wire surface impurities leads to a rapid increase in manufacturing costs. If any one of the above elements exceeds 0.05% by weight, arc instability increases and adverse effects such as an increase in cracking susceptibility are caused. Further, even if the total amount of these elements exceeds 0.50% by weight, the same adverse effect is exerted.
50% by weight or less is desirable.

In addition to the above-mentioned components, one or more of the following components may be contained in an appropriate amount, if necessary. Ni: 0.01 to 1.80% by weight Ni is an effective component for obtaining low-temperature toughness and strength of the weld metal, but if it is less than 0.01% by weight, both low-temperature toughness and strength are insufficient. On the other hand, if the content exceeds 1.80% by weight, hot cracking is liable to occur in the weld metal.
It is desirably from 0.01 to 1.80% by weight.

Cr: 0.01-0.70% by weight Cr is an effective component for obtaining the strength of the weld metal.
Less than 0.01% by weight is not sufficient.
If the content is more than 0.01% by weight, elongation of the weld metal tends to be insufficient, and low-temperature cracking tends to occur.
０．７0.70% by weight is desirable.

Mo: 0.01 to 0.65% by weight Mo is an effective component for obtaining low-temperature toughness and strength of the weld metal, but if it is less than 0.01% by weight, both low-temperature toughness and strength are insufficient. Yes, and when it exceeds 0.65% by weight,
A high temperature crack is easily generated in the weld metal, and the elongation of the weld metal is apt to be insufficient, so that 0.01 to 0.65% by weight is desirable.

Al: 0.01 to 0.50% by weight Al is an effective component for deoxidizing the weld metal and shaping the weld bead. Is insufficient, and if it exceeds 0.50% by weight, hot cracks are likely to occur in the weld metal. Therefore, 0.01 to 0.50% by weight is desirable.

Ti + Zr: 0.01 to 0.30 wt% Both Ti and Zr are effective components for deoxidizing the weld metal and reducing spatter. Therefore, Ti and Zr are added singly or in combination, but when the total amount is less than 0.01% by weight, both deoxidation and reduction of spatter are insufficient, and 0.30% by weight If it exceeds, the hot metal tends to crack at high temperature.
30% by weight is desirable. Also, Ti is more effective in reducing spatter than Zr, and the Ti content is reduced to Zr.
It is more desirable to increase the content of r.

[0049]

Next, an embodiment of the present invention will be described. After rolling or drawing, heat-treat as necessary, then wash, copper plating, washing, finishing wire drawing, washing, oil supply for feed or rust prevention, spool rewind or Each step of the large-capacity pack manufacturing process was sequentially performed.
The conditions of each step were appropriately changed. The diameter of the obtained welding wire is 1.2 mm. About these welding wires, the amount of wire surface impurities, the ratio of large wire surface impurities of 10 μm or more, the ratio of copper in the wire surface impurities,
When the relationship between the Ca amount and the surface Ca amount and the arc stability, the sensory workability, and the fatigue of the operator was examined, the results shown in Tables 1 and 2 below were obtained.

Further, the relationship between the amount of Na, the amount of K, the amount of Na on the solid surface, and the amount of K on the solid surface, and the sensory workability and the fatigue of the operator were examined. The results shown in Table 3 below were obtained. Was.

Further, the relationship between the total oxygen content and the surface oxygen content, and the sensory workability and the fatigue of the worker was examined.
The results as shown in Table 4 below were obtained.

The wire surface impurity amount, surface Ca amount, solid surface Na amount, solid surface K amount, total oxygen amount, and surface oxygen amount in each table are the amounts measured by the above-described methods.

Regarding arc stability, DCEP
(DC, wire plus), welding current: 220 A, arc voltage: 30 V, welding time: 60 cm / min, shielding gas:
Measure the change in arc voltage under the welding conditions of CO ₂ , 40V
The above was judged as arc break, and the number of occurrences per second was examined.

Regarding the sensory workability and the fatigue of the worker, DCEP, welding current: 250 A to 340 A, arc voltage: 32 V to 34 V, welding time: 20 to 40 cm /
And shielding gas: CO ₂ welding conditions.

The solid wire used had the following chemical components: C: 0.04% by weight; Si: 0.75% by weight;
n: 1.70% by weight, P: 0.015% by weight or less, S:
0.010% by weight, Cu; 0.25% by weight, Ni;
02% by weight, Cr: 0.04% by weight, Mo: 0.005
% By weight, Al: 0.008% by weight, Ti: 0.18
Including the weight, the balance is Fe of 96.5% by weight or more and inevitable impurities.

[0056]

[Table 1]

[0057] However, in Example 1 to 1 8 Ru der corresponds to claim 1. Comparative Examples 19 to 23 are claimed in claim 1.
It is out of the question.

[0058]

[Table 2]

However, in Table 2, the sensory workability is a case where 1 is inferior, 2 and 3 are good, 4 and 5 are excellent, and the larger the number, the better.

Further, the fatigue of the worker is 1 when the feeling of fatigue is large, 2 and 3 are good, and 4 and 5 are cases where the feeling of fatigue is small. Also in this case, the larger the number, the better the feeling of fatigue.

[0061]

[Table 3]

However, Embodiments 24 to 31 correspond to claim 2 , and Embodiments 32 to 40 correspond to claim 3 . Further, Comparative Examples 41 to 44 are described in the claims.
It is out of 2 or 3 , and Claim 1 is satisfied.

Wire surface impurities: 3 to 4 μg / cm ² Wire surface impurities of 10 μm or more: 5 to 35% by weight Copper in wire surface impurities: 50 to 95% by weight Ca content of wire: 3 ppm or less Wire surface Ca Amount: 1 ppm or less Sensory workability: 1 (poor) -2-3 (good) -4-5
(Excellent) Worker fatigue: 1 (large) -2-3 (good) -4-5
(small).

[0064]

[Table 4]

Examples 45 to 54 correspond to claim 4 of the present invention, and comparative examples 55 to 61 depart from claim 4 , but claim 1 satisfies.

However, wire surface impurities: 3 to 4 μg / cm ² Wire surface impurities of 10 μm or more: 5 to 35% by weight Copper in wire surface impurities: 50 to 95% by weight Ca content of wire: 3 ppm or less Wire surface Ca Amount: 1 ppm or less Na content of wire: 0.8 to 2.5 ppm K content of wire: 0.7 to 2.9 ppm Solid surface Na content of wire: 0.5 to 2.4 ppm Solid surface K content of wire: 0 0.5 to 2.8 ppm Sensory workability: 1 (poor) -2-3 (good) -4-5
(Excellent) Worker fatigue: 1 (large) -2-3 (good) -4-5
(small).

As can be seen from these tables, the welding wire of the example of the present invention has an excellent effect as compared with the welding wire of the comparative example.

That is, in Tables 1 and 2, as shown in Examples 1 to 13 of the present invention, the amount of impurities on the wire surface was reduced to 5 μg or less per 1 cm ^{2 of the} apparent surface area of the wire, and the amount of Ca in the wire was reduced to 10 ppm or less. Further, it can be seen that by setting the surface Ca content to 3 ppm or less, the arc becomes stable, the workability is improved, and the fatigue of the worker is reduced. It is better that the wire surface impurity amount, the Ca amount, and the surface Ca amount are small, and the arc can be further stabilized if they can be 2 μg or less, 3 ppm or less, and 1 ppm or less, respectively.

Tables 1 and 2 show that Examples 14 to 1
As shown in FIG. 8, even better results can be obtained by setting the ratio of wire surface impurities having a size of 10 μm or more to 40% by weight or less and the ratio of copper in the wire surface impurities to 30% by weight or more. .

Table 3 shows that Example 24 of the present invention was obtained.
As shown in FIGS. 31 to 31, Na and K are each 10 ppm or less,
Further, it can be seen that by containing 0.1 ppm or more of Na and / or K, the arc can be stabilized and the fatigue of the operator can be reduced. Na and K are preferably in the range of 0.2 ppm to 5 ppm, in which case the arc can be further stabilized.

In Table 3, as shown in Examples 32 to 40, solid surface Na and / or solid surface were added to the wire solid surface portion.
Or by including the solid surface K 0.1ppm or more,
Further, it can be seen that the arc can be stabilized and the fatigue of the operator can be reduced. 0.2 pp solid surface Na and solid surface K
The range is preferably from m to 5 ppm. In this case, the workability can be further improved and the feeling of fatigue can be reduced.

In Table 4, as shown in Examples 45 to 54, when the total oxygen content is 30 ppm to 200 ppm or less and the surface oxygen content is 20 ppm to 180 ppm,
It can be seen that the fatigue of the worker can be reduced. Further, it can be seen that by setting the surface oxygen content from 30 ppm to 100 ppm, the arc can be further stabilized and the fatigue of the operator can be greatly reduced. At this time, a uniform crack-like surface crack was observed on the wire surface.

In these steps, the steps after the heat treatment contributed significantly, and sufficient results could not be obtained unless proper management was performed in each step.

If the wire surface is not damaged as much as possible in each cleaning step, when the wire is used, the wire surface is easily peeled off by contact with the flexible conduit tube, and the feeding is hindered. become.

Similar results are obtained not only with the 1.2 mm diameter wire shown in Table 1, but also with wires having other diameters and components. Similar results have been obtained with copper-plated flux cored wires.

[0076]

As described above, according to the present invention,
A wire in which the wire surface impurity amount and the Ca amount on the wire surface are within predetermined ranges significantly improves the stability of the welding arc, hardly causes welding defects due to arc instability even at high-speed welding, and causes fatigue of workers. And the quality and work efficiency are improved. Thus, the present invention makes a great contribution in the technical field of performing gas shielded arc welding.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-80196 (JP, A) JP-A-1-249291 (JP, A) JP-A-4-327395 (JP, A) JP-A-62-162 248594 (JP, A) JP-A-2-46994 (JP, A) JP-A-7-164185 (JP, A) Minoru Kobayashi, ed. ), Japan Standards Association, pp. 213-215

Claims (6)

(57) [Claims] 1. The method according to claim 1, wherein impurities on the surface of the wire are restricted to 5 μg or less per 1 cm ^{2 of the} apparent surface area of the wire.
Among the impurities, filter paper with a pore size of 10 μm (membrane fill
The mass of the material that does not pass through
Restricted to 40% by weight or less of mass
Of copper component (converted to copper in case of copper compound)
A gas shielded arc welding wire characterized in that the amount of Ca is controlled to 10 % or less, and the amount of Ca in the entire wire is regulated to 3 ppm or less. 2. The gas shielded arc welding wire according to claim 1, wherein Na and / or K are contained in the entire wire containing the wire surface impurities in an amount of 0.1 to 10 ppm, respectively. 3. The gas shielded arc welding wire according to claim 2, wherein the solid surface portion of the wire contains solid surface Na and / or solid surface K in a total amount of 0.1 ppm or more. 4. The total oxygen content of the wire is 30 to 200 pp.
The gas shielded arc welding wire according to claim 3, wherein the wire has a surface oxygen content of 20 to 180 ppm. 5. The composition of the wire is C: 0.001 to 0.5.
15% by weight, Si: 0.30 to 1.10% by weight, M
n: 0.85 to 2.60% by weight, P: 0.001 to 0.030% by weight, S: 0.001 to 0.030% by weight, Cu: 0.01 to 0.50% by weight. The wire for gas shielded arc welding according to claim 4, wherein the balance is iron and inevitable impurities. 6. The composition of the wire is C: 0.001 to 0.5.
15% by weight, Si: 0.30 to 1.10% by weight, M
n: 0.85 to 2.60% by weight, P: 0.001 to 0.030% by weight, S: 0.001 to 0.030% by weight, Cu: 0.01 to 0.50% by weight. Ni: 0.01 to 1.80% by weight; Cr: 0.0
1 to 0.70% by weight, Mo; 0.01 to 0.65% by weight, Al: 0.01 to 0.50% by weight and [Ti +
5. The gas shield according to claim 4, wherein the gas shield contains at least one component selected from the group consisting of Zr]: 0.01 to 0.30% by weight, with the balance being iron and unavoidable impurities. Wire for arc welding.